The invention relates to an alarm system for a marine drive for providing a warning of abnormal engine conditions such as high temperature or low oil pressure. The invention arose from efforts to provide an additional warning system, beyond the normal gauges already present, without altering or adding wires to the wire harness between the engine and the helm.
In a marine drive, a wiring harness is connected between the engine and the boat helm for completing various circuits therebetween. The engine typically includes various sensors for sensing given conditions of the engine, such as temperature and oil pressure. The helm typically includes various gauges for indicating sensed the engine conditions. The wiring harness includes a wire dedicated to the temperature sensing function and connected between the engine temperature sensor and the temperature gauge at the helm, and another wire dedicated to the oil pressure sensing function and connected between the engine oil pressure sensor and the oil pressure gauge at the helm.
It is cost-objectionable to alter or add to the existing wiring harness. The present invention enables the addition of an engine condition warning system without requiring changes to the existing controls or wiring harness. In the present invention, a single wire in the harness services both the gauge function and the alarm function, and allows the addition of the alarm without requiring an additional wire. This is desirable because it leaves intact the existing wiring harness between the engine and the helm.